# updateLambdaWithId

Updates the lambda with the given Id.

Agent View of the PolicyLayer registry record for `updateLambdaWithId`. HTML page: https://policylayer.com/tools/io-fusionauth-mcp-api/updatelambdawithid

## Facts

- Tool: `updateLambdaWithId`
- Server: Fusionauth (`@fusionauth/mcp-api`) — https://policylayer.com/tools/io-fusionauth-mcp-api.md
- Install: `npx -y @fusionauth/mcp-api`
- Homepage: https://github.com/FusionAuth/fusionauth-mcp-api
- Risk category: Write (Medium risk)
- Registry record: grade F, identity unverified
- Server rate-limited: no
- Parameters: 0
- Recommended policy verdict: Rate-limited

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "updateLambdaWithId",
    "arguments": {}
  }
}
```

## Why updateLambdaWithId is rated Medium

This is a Write operation because it modifies existing lambda resources reversibly. However, it carries high severity because lambdas in FusionAuth control core authentication and authorization logic—misconfigured or malicious lambdas could compromise security across the system, even though the action itself is theoretically reversible.

From the tool's own definition: "Tool name 'updateLambdaWithId' and description 'Updates the lambda with the given Id' indicate modification of existing data (lambda configuration/code)."

## Use case

AI agents use updateLambdaWithId to create or update resources in Fusionauth, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Fusionauth environment.

## Recommended policy (PolicyLayer)

Verdict: **Rate-limited**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Fusionauth:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "updateLambdaWithId": {
      "limits": [
        {
          "counter": "updatelambdawithid_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}
```

## Other tools on Fusionauth (313)

- `deleteAPIKeyWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteapikeywithid.md
- `deleteApplicationRoleWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteapplicationrolewithid.md
- `deleteApplicationWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteapplicationwithid.md
- `deleteConnectorWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteconnectorwithid.md
- `deleteConsentWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteconsentwithid.md
- `deleteEmailTemplateWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteemailtemplatewithid.md
- `deleteEntityGrantWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteentitygrantwithid.md
- `deleteEntityTypePermissionWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteentitytypepermissionwithid.md
- `deleteEntityTypeWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteentitytypewithid.md
- `deleteEntityWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteentitywithid.md
- `deleteFormFieldWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteformfieldwithid.md
- `deleteFormWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteformwithid.md
- `deleteGroupMembersWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deletegroupmemberswithid.md
- `deleteGroupWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deletegroupwithid.md
- `deleteIdentityProviderWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteidentityproviderwithid.md
- `deleteIPAccessControlListWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteipaccesscontrollistwithid.md
- `deleteJwtRefresh` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deletejwtrefresh.md
- `deleteKeyWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deletekeywithid.md
- `deleteLambdaWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deletelambdawithid.md
- `deleteMessageTemplateWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deletemessagetemplatewithid.md
- `deleteMessengerWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deletemessengerwithid.md
- `deleteOAuthScopeWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteoauthscopewithid.md
- `deleteTenantWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deletetenantwithid.md
- `deleteThemeWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deletethemewithid.md
- `deleteUserActionReasonWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteuseractionreasonwithid.md
- `deleteUserActionWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteuseractionwithid.md
- `deleteUserBulk` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteuserbulk.md
- `deleteUserLinkWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteuserlinkwithid.md
- `deleteUserRegistrationWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteuserregistrationwithid.md
- `deleteUserTwoFactorWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteusertwofactorwithid.md
- …and 283 more: https://policylayer.com/tools/io-fusionauth-mcp-api.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

---

Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=io-fusionauth-mcp-api · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/io-fusionauth-mcp-api